Enjoying music

I'm trying to learn more about music quality and getting the most out of my current setup (or how to reasonably / efficiently upgrade). I don't really know where to start, though. For my home setup, I have a pretty basic Denon receiver and a couple KEF speakers, while my portable setup is an iPod classic (the retro 160gb...most songs 200kpbs+) and a pair of Grado rs1i headphones. What am I supposed to do?

Btw - I'm targeting this more for portable music than staying at home.